Recently, an apparatus in which letters and images printed on a paper are decolored so that the paper can be used again, has become practicable. Such an apparatus has an advantage that the paper, which is decolored can be used many times and paper can be saved. However, there are some apparatus in which printing without decoloring is preferable depending on a content of printed data. In addition, an image forming apparatus that includes a mechanism which performs printing using a general non-decoloring recording material and a mechanism which performs printing using a decolorable recording material is known.